1. Field of the Invention
The disclosed subject matter relates to thermosetting polymer-based composite materials. More specifically, the disclosed subject matter relates to lead-free, non-toxic thermosetting polymer-based composite materials, which may be used in radiation shielding, weight-balancing, ballast or energy storage applications.
2. Description of Related Art
Lead has been used in many industries for decades. For instance, lead is widely used for radiation shielding applications due to its efficiency and low cost. While efficient and low-cost, lead has been found to be toxic to animals, and particularly toxic to humans.
In response to the desire to reduce toxicity or the use of toxic compounds, and in order to comply with state, federal and international regulations regarding the use, transport and disposal of lead and lead-containing composites materials, numerous lead substitutes and lead-free composite materials have been developed as replacements for lead or lead-filled composite materials. Lead substitutes and lead-free composite materials can be used in a variety of applications, including, but not limited to ammunition, construction and radiation shielding applications.
While lead-free composite materials developed for use in radiation shielding applications thus far may offer the benefit of reduced or no toxicity, it has been found that lead-free composite materials containing fillers in certain amounts increase the viscosity of the composite material. At certain levels of filler content, viscosity becomes so high that the ability to cast the material is reduced or lost completely. As is appreciated to one of ordinary skill in the art, it is desirable to not only have a non-toxic composite material for use in radiation shielding applications, but to have a material that is easily used in making final products. Accordingly, any reduction or loss of the ability to cast the composite material may be challenging when lead-free composite materials are utilized.
A lead-free, non-toxic composite material that is efficient in radiation protection, economical to make and use as well as easily handled and castable or processed by other methods, such as liquid phase sintering, is desired.